Meteorological mechanisms of regional PM 2.5 and O 3 transport in the North China Plain driven by the East Asian monsoon

Atmospheric Pollution Research

article

Shuang Liu¹  Wenhui Zhao²  Lingjun Li²  Jiannan Jin¹  Tianze Li³  Haitao Xu¹  Wenji Zhao¹ 

[1] College of Resource Environment and Tourism, Capital Normal University;Beijing Municipal Ecological and Environmental Monitoring Center;Beijing University of Civil Engineering and Architecture

关键词: Meteorological mechanism;    MV-EOF;    O 3;    O 3 sensitivity;    PM 2.5;    Regional transport;   

DOI  :  10.1016/j.apr.2022.101638

学科分类：农业科学（综合）

来源: Dokuz Eylul Universitesi * Department of Environmental Engineering

【 摘 要 】

The regional transport of air pollutants significantly affects downwind air quality in the North China Plain (NCP), which forms part of the East Asian monsoon region. Here, we investigated the meteorological regional transport mechanisms that lead to wintertime PM 2.5 and summertime O 3 pollution episodes in downwind regions over the NCP during the East Asian monsoon. First, we analyzed the spatiotemporal patterns of PM 2.5 and O 3 pollution during the summers and winters of 2015–2020 in the NCP, as well as the influence of meteorological conditions. Subsequently, we identified the typical regional transport patterns of wintertime PM 2.5 and summertime O 3 using the multivariable empirical orthogonal function with multi-source data. The results showed that prevailing southerly and southeasterly winds in summer aggravated PM 2.5 and O 3 pollution over the northern NCP. Conversely, prevailing northerly and northwesterly winds in winter exacerbated PM 2.5 and O 3 pollution over the southern NCP. Wintertime PM 2.5 pollution events in Henan (on the southern edge of the NCP) were induced by the southward movement of weak cold airflow following northerly winds governed by the East Asian winter monsoon. Additionally, a warm air mass to the south of Henan and the high surrounding terrain inhibited further southward invasion of weak cold air, causing heavy PM 2.5 pollution. Conversely, summertime O 3 pollution episodes in Beijing (on the northern edge of the NCP) were associated with southerly and southeasterly winds, which drove the transport of O 3 and its precursors from the southern NCP to Beijing. The mountain barrier in northern Beijing aggravated O 3 pollution. During the O 3 pollution events, Beijing was in a transitional regime, and HCHO and NO 2 increased by 17.16% and 20.43%, respectively. Furthermore, the vertical structure of the atmosphere facilitated the downward mixing of PM 2.5 and O 3 transported during pollution episodes. These results provide a theoretical reference for predicting and controlling heavy air pollution in the NCP.

【 授权许可】

CC BY